1st generation modernization began in late 1990s, which leveraged CICS based transactions for eCommerce, IVR and CRM integration with IBM MQ and custom CICS brokers. High volume CICSPLEX deployment processing over 2 million messages per day.
2nd Generation modernization implemented WebSphere Liberty Web container in CICS for serving up REST APIs at the edge of the CICSPLEX. Composition APIs provided by CICS COBOL services rather than ESB. This approach moves mapping from the middleware team to the Mainframe team.